The biggest factors, from what I can tell, are age and rebuild cost. 

Partnering with local experts who understand zoning, permitting, and market nuances can help you avoid costly mistakes and maximize returns.If you're in a high-cost area, out-of-state investing can provide access to markets with better entry points and higher ROI potential.

It was mostly due to my day job income and low cost of living over a long period of time; however, real estate accounts for about 50% of our income through a small portfolio of short, mid, and long term rentals. 

Many times they will hold back the renovation costs in escrow and release once you’ve shown the renovated unit and leased it.  

The changes that have occurred in the past year is making sure the comps are truly there, getting the material costs down (or accurate) number with changes all the time on costs. 3.

The 2-3% points in extra cost are worth it if you plan on using as I described above because the use would be for a few  months at most and due to that short term use you can survive a rate adjustment up.But, if you have no plan to payoff the debt like when using for a down payment on a long term hold why pay the extra cost for flexibility and have the additional risk of the adjustable rate with the amortization looming when you can get a fixed rate second mortgage. 

You have 3 months (potentially) to get it all sorted which should be pretty easy.If someone is selling a STR, that doesn't mean there are issues.

There are also additional costs of operating and maintaining an LLC, like separate bank accounts, annual report filings, tax filings, etc.2.

Also make sure you are comfortable with some holding costs if the units don't get rented right away (if vacant).Also look into if there is rent control in the area that the property is located.

This is how I see it:Single-Family Homes:Pros:Larger pool of potential tenants (families).Simpler management (one tenant, one lease).Often easier to finance.May appreciate faster in some markets.Cons:Only one income stream.Vacancy hits harder financially.Duplexes:Pros:Two potential income streams.Live in one unit and rent the other (house hacking!)